Selecting elite groundnut (Arachis hypogaea L) genotypes for symbiotic N nutrition, water-use efficiency and pod yield at three field sites, using 15N and 13C natural abundance

Abstract

About 70% of the groundnut (Arachis hypogaea L.) produced in Ghana is from the Guinea savanna. However, low soil nutrients, especially N, together with erratic rainfall distribution have often resulted in poor grain yield. The aim of this study was to evaluate plant growth, N2-fixing efficiency, N contribution, water-use efficiency and pod yield of 21 elite groundnut genotypes in the Guinea savanna of Ghana, using the 15N natural abundance technique. The data revealed significant variations in plant growth, symbiotic N contribution, and pod yield among the 21 genotypes tested at each field site. Average N contribution by groundnut genotypes ranged from 48 to 108 kg N ha−1. Also, mean pod yield ranged from 0.58 to 2.1 t ha−1. Genotypes ICGV-IS 08837, ICG 6222, ICGV 03315 and NKATIESARI demonstrated superior plant growth, symbiotic N contribution and greater pod yield. In fact, ICGV-IS 08837 yielded almost 2.5 fold more than CHINESE which is the most widely cultivated variety in the region. Genotypes ICGV-IS 08837, ICG 6222, ICGV 03315 and ICGV 99247 are therefore recommended for development into varieties for the Guinea savanna of Ghana. Genotypes ICG (FDRS) 4, ICGV00362 and ICGV99247 exhibited increased water-use efficiency, but were low in N2 fixation and N contribution, and would therefore be good parental material in breeding programs aimed at enhancing water-use efficiency in high N2-fixing genotypes.

Screening Cowpea (<i>Vigna unguiculata</i> (L.) Walp.) Genotypes for Enhanced N<sub>2</sub> Fixation and Water Use Efficiency under Field Conditions in Ghana

“…Like most legumes, the N 2 -fixing trait of cowpea confers adaptation to low nutrient soils, with some genotypes deriving up to 96% of their nitrogen (N) requirements from symbiosis, which often leads to significant N contribution to cropping systems and grain yield increases [1] [4] [5]. However, due to variations in legume symbiotic performance resulting from genotypic differences and N 2 -fixing efficiency of the rhizobial symbionts, there is often the need to screen for improved N 2 fixation among legume germplasm [6] [7]. Of the many techniques used to estimate legume symbiotic performance, the 15 N natural abundance has so far been useful in quantifying N 2 fixation in field-grown legumes [8] [9].…”

Potential Contribution of Groundnut Residues to Soil N and the Influence of Farmer Management in Western Uganda

“…In other words, we assumed 70, 50, or 30% of total plant N was mined from the soil rather than obtained via BNF. These proportions of N derived via BNF fall within the range of published groundnut N and fixation values for SSA (Kanmegne et al, 2006;Ncube et al, 2007;Ojiem et al, 2007;Ebanyat et al, 2010b;Nyemba and Dakora, 2010;Mokgehle et al, 2014;Franke et al, 2018;Kermah et al, 2018;Oteng-Frimpong and Dakora, 2018). We multiplied the crop N by the proportion of N derived via BNF to find the fixed N (fixed N, kg N ha −1 ).…”

Evaluation of elite soybean (Glycine max L.) genotypes for nitrogen nutrition, water use efficiency and grain yield in the Guinea Savanna Agro Ecological Zone of Northern Ghana

“…Research findings by Lammel et al (2018) reported that low and high soil pH can indirectly affect crop growth and development by affecting the availability of nutrients needed by crop for its growth and development. Grain legumes have been found to fix between 15 and 201 kg N ha -1 per season in the West African Guinea savanna (Dakora et al, 1987;Oteng-Frimpong and Dakora, 2018;Sanginga et al, 2002). Groundnut (Yusuf et al, 2009), soybean (Sanginga et al, 2002) and cowpea (Dakora et al, 1987) have been shown to contribute up to 48 kg N ha -1 , 43 kg N ha -1 and 125 kg N ha -1 , respectively to the soil.…”